1. Field of the Invention
The present invention generally relates to a user input device and method, and in particular, to a user input device and method in a mobile terminal having a touch screen and a fingerprint recognition sensor.
2. Description of the Related Art
Generally, a user input unit of a handheld device, such as a mobile communication terminal, is comprised of a keypad. Users can input data by directly pressing button keys provided on a keypad or using a touch screen. Data input using a touch screen can be soft keyboard input or handwriting recognition. A soft keyboard is an on-screen keyboard generated on a touch screen, which enables a user to input data using a digital pen. The soft keyboard overcomes the lack of portability of general input devices, i.e. keyboard and mouse. A handwriting recognition software allows a user to provide input by writing on a touch screen. It recognizes the user's handwriting and converts the handwriting input into a data code. Mobile terminals, such as electronic schedulers, mobile phones and PDAs, are generally provided with a touch screen.
Users can select a specific operation mode, such as a call mode or a text input mode, under a mode menu displayed on the touch screen, and input numbers, characters or special characters to implement the selected operation mode. In other words, a general operation mode can be selected by a number of key inputs for selecting a menu and a sub-menu corresponding to the mode. Even a frequently used operation mode can be selected in the same manner. A more rapid and simplified method for selecting a desired operation mode is highly demanded.
Due to the trend toward small designs, a touch screen provided on a mobile terminal is also becoming smaller with reduced size of a soft keyboard. Users may select a desired operation mode and input a telephone number or a text message in the selected mode using the soft keyboard displayed on the small touch screen. Every key of the soft keyboard has a small size, for example, 4×4 mm, to be displayed on the small touch screen. Users may have some difficulty using the small-sized keys of the soft keyboard accurately. They may often press a wrong key during the input of data. Since all keys for inputting characters, numbers and special characters/symbols are provided on the soft keyboard, an actual area of displaying the inputted data is inevitably reduced. Also, terminals with a large number of keys displayed on the soft keyboard may go against the demand for small designs.